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Miyashita M.,SoftBank Telecom Corp | Omote H.,SoftBank Telecom Corp | Yamaguchi R.,SoftBank Telecom Corp
2015 International Symposium on Antennas and Propagation, ISAP 2015 | Year: 2015

In order to overcome the increasing traffic problems of mobile terminals used in high-rise floors of buildings, the three-dimensional cell configuration which places small cells on various floors is considered. In order to evaluate the wireless transmission technology for the three-dimensional cell configuration, it is necessary to clarify the time-spatial characteristics which encompass the characteristics of the path loss, the delay profile and the spatial arrival angular profile for waves travelling from one indoor space in a high-rise office to another such indoor space. In this paper, we measure the path loss characteristics of radio waves passing from one indoor space to another and identify the key parameters for the path loss characteristic based on measured results. Further, we compare measured and simulation (ray tracing) results. Finally, we use the simulation results to analyze the relation between the parameters and path loss characteristics. © 2015 The Institute of Electronics, Information and Comm.

Omote H.,SoftBank Telecom Corp | Sugita Y.,SoftBank Telecom Corp | Ohta Y.,SoftBank Telecom Corp | Fujii T.,SoftBank Telecom Corp
Proceedings of 6th European Conference on Antennas and Propagation, EuCAP 2012 | Year: 2012

In order to evaluate spatial processing techniques such as MIMO for wideband mobile communications, a Time-Spatial Propagation (TSP) model is required. The Time-Spatial profile consists of the delay profile, the spatial arrival angular profiles at the base station (BS) and the mobile station (MS) for traveling waves. One key parameter of the TSP model is carrier frequency. We have proposed a Time-Spatial profile prediction formula for wideband mobile communication systems in Non-line of sight (NLOS) environments and clarified that the Time-Spatial profile does not depend on the carrier frequency. We have also carried out measurements to develop the Time-Spatial profile prediction formula for Line of sight (LOS) environments. In this paper, we evaluate the carrier frequency characteristics of the Time-Spatial profile in Line of sight (LOS) environments based on the measurement data, and show that our proposed Time-Spatial profile prediction formula in LOS environments is valid for various carrier frequencies. © 2012 IEEE.

Nagai Y.,SoftBank Telecom Corp | Okamawari T.,SoftBank Telecom Corp | Fujii T.,SoftBank Telecom Corp
IEEE Vehicular Technology Conference | Year: 2016

Recently, mobile video streaming services become very popular. MPEG-DASH is one of the streaming schemes used for the service. In this method, a mobile terminal tries to download video chunks from a streaming server by estimating the available bandwidth of the underlying network. However, it is very difficult to estimate the available bandwidth because this method is working as an OTT (over the top) service, which means the network is regarded as a dumb pipe. Therefore some of the downloaded video chunks are discarded when the estimation is wrong. Since wireless spectrum is a very precious resource, the wasted chunks (downloaded then discarded) should be avoided. We propose a novel video streaming method in which a QoS (Quality of Service) control function of a mobile network is utilized. In the proposed method, an original video content is encoded into multiple layers. There are two kinds of layers, a base layer and an enhancement layer. The base layer is small in size but includes all the necessary information to keep playing the video content. The enhancement layer is large in size and provides better image quality when decoded with a corresponding base layer. Then the base layer is prioritized by the QoS control function in the mobile network when it is delivered to a mobile terminal. On the other hand, the enhancement layer is delivered in a best effort manner. In this way, even if there were no available bandwidth for both of the layers, the mobile terminal can keep playing the video by using the prioritized base layer. Since the enhancement layer is discarded before the wireless transmission when it is congested, the wireless spectrum is efficiently used. © 2016 IEEE.

Zhang L.,SoftBank Telecom Corp | Okamawari T.,SoftBank Telecom Corp | Fujii T.,SoftBank Telecom Corp
IEEE Wireless Communications and Networking Conference, WCNC | Year: 2012

LTE (Long Term Evolution) has been standardized in 3GPP (3 rd Generation Partnership Project) to provide higher data throughput as well as lower latency for various IP based services including web browsing, VoIP (Voice over IP), video streaming and so on. In this paper, we evaluate the performance of TCP and UDP when handover is executed in an LTE system. The performance is degraded due to the interference between source and target eNBs (evolved NodeB). Also the handover interruption time negatively affects overall performance. We measure the TCP throughput and the transmission delay of UDP during the handover process by using our indoor and outdoor LTE testbeds. The results show that better TCP throughput performance is obtained by decreasing the A3-offset and the interruption time caused by a handover event is around 80ms. © 2012 IEEE.

SoftBank Telecom Corp | Date: 2014-12-17

A communication system controls routing performed by a physical gateway that connects a mobile station and a communication network. The communication system comprises a communication setting information acquiring unit and a routing control unit. The communication setting information acquiring unit acquires communication setting information between a virtual gateway corresponding to the physical gateway and the mobile station by executing a communication establishment sequence between the virtual gateway and the mobile station. The routing control unit controls routing performed by the physical gateway based on the communication setting information.

Nagai Y.,SoftBank Telecom Corp | Okamawari T.,SoftBank Telecom Corp | Fujii T.,SoftBank Telecom Corp
IEEE Wireless Communications and Networking Conference, WCNC | Year: 2016

Nowadays mobile video streaming services become very popular. However, due to the drastic bandwidth fluctuation in a mobile network, the quality of the mobile video streaming degrades significantly. Above all, mobile users are not happy when video image freezes for a few seconds/minutes. Most of current video streaming services are working as an OTT (over the top) service, which means a mobile network is regarded as a dumb pipe. Therefore it is very difficult to handle the fluctuation. We propose a novel video streaming method in which a QoS control function of a mobile network is utilized to prevent the video image from freezing. In the proposed method, an original video content is encoded into a sequence of video frames with multiple layers. There are two kinds of layers, a base layer and an enhancement layer. The base layer is small in size but includes all the necessary information to play the original content. The enhancement layer is large in size and provides better image resolution when decoded with a corresponding base layer. Then the base layer is prioritized by the QoS control function in the mobile network when it is delivered to a mobile terminal. On the other hand, the enhancement layer is delivered in a best effort manner. In this way, the mobile terminal can receive the base layer even when wireless signal is degraded and the video image dose not freeze at all. The proposed method is evaluated experimentally using a prototype system. The result of the evaluation shows that the proposed method works properly as we designed. © 2016 IEEE.

Miyashita M.,SoftBank Telecom Corp | Mikami M.,SoftBank Telecom Corp | Fujii T.,SoftBank Telecom Corp
IEEE Vehicular Technology Conference | Year: 2015

Recently, data traffic is explosively increasing in cellular mobile communication systems due to the prevalence of smart phones. A heterogeneous cellular network overlaid with small-cells to a macro-cell (HetNet), in which small-cell base stations (BSs) with a low transmission power are placed at the hot spot area of a macro-cell base station with a high transmission power, has been receiving attention in order to deal with the increasing traffic. For HetNet, Cell Range Expansion (CRE), in which a bias value is used for the reference signal received power (RSRP) from small-cell BSs, has been investigated as a promising approach to offload the traffic into the small-cell from the macro-cell. However, User Equipments (UEs), located in the small-cell area expanded by CRE, suffers large inter-cell interference (ICI) from the macro-cell BSs for the case of co- channel HetNet in which the same carrier frequency is used between macro-cells and small-cells. Hence, it is required for co-channel HetNet to mitigate ICI. In order to improve the downlink user throughput characteristics for co-channel HetNet employing large CRE bias value, this report investigates a successive interference cancellation (SIC) technique of codeword level SIC. The codeword level SIC (CWSIC) realizes a large ICI mitigation effect employing the output of the channel decoder for interference signals. Simulation results confirm that CWSIC based on soft replica effectively mitigate the ICI from the macro-cell BSs, compared to CWSIC based on hard replica. © 2015 IEEE.

News Article | February 10, 2015

IBM and SoftBank have teamed to deliver IBM's Watson cognitive computing technology to the technology-thirsty Japanese market. IBM announced an agreement with SoftBank Telecom Corp to bring IBM’s Watson cognitive computing technology to Japan, the world’s third-largest economy and second-largest technology market. The partnership, which involves training Watson to understand Japanese, represents a major milestone in IBM's efforts to accelerate the adoption of cognitive computing and  SoftBank’s work to  transform Japanese businesses and society. The goal of the collaboration is to bring new Watson-powered apps and services  to market in the region. To do this, IBM and SoftBank will establish  a broad local ecosystem of partners, entrepreneurs, and app developers who will apply Watson in new and innovative ways. “The partnership with SoftBank, an industry pioneer, will bring new Watson capabilities to organizations in one of the most innovative parts of the world,” said Mike Rhodin, senior vice president of the IBM Watson Group, in a statement. “Watson’s technology, which analyzes large volumes of data, and can understand and answer complex questions posed in natural language, is in harmony with SoftBank Group's corporate mission of ‘Information Revolution - Happiness for Everyone,’” said Ken Miyauchi, representative director and chief operating officer at SoftBank, in a statement. “We believe the technology will be applied to a broad range of areas, from enterprise to consumer sectors, and create new value for people.”As part of the collaboration, IBM and SoftBank intend to deliver new powered by Watson cloud-based services.  The two organizations will initially target Japan’s education, banking, healthcare, insurance and retail industriesThe alliance builds upon an ongoing, joint technical collaboration around cognitive computingtechnology between SoftBank and IBM Research – Tokyo. Watson’s ability to understand Japanese is the result of more than two decades of research and development undertaken by IBM Research in the areas of natural language processing, both in Japanese and other non-European languages. Japanese uses thousands of characters, many of which can carry different meanings and pronunciations depending on the context of conversation, the relationships between participants, their age and gender. Like any major language, there are many unique idioms that must be fully understood for natural human interaction, IBM said.“The Japanese language presented IBM researchers with a number of unique challenges to overcome, most notably the first time the Watson system has learned a language that relies on characters not shared by the Western alphabet," said Paul Yonamine, general manager of IBM Japan. “Watson will deliver innovation to the academic, government services, and various industries, while improving overall agility and decision making for our clients. SoftBank and IBM will apply the technology in multiple industries and business domains to usher in a new era of computing in Japan.” To capture new and emerging opportunities, IBM and SoftBank will focus on expanding Watson’s knowledge by further training it in the Japanese language and various industry domains; developing localized APIs and development environments made available through the Watson Developer Cloud ,  and building and expanding the Watson ecosystem. SoftBank will be IBM’s preferred technology delivery partner for Watson solutions in Japan, where the technology could be embedded into various form factors such as desktop, tablets and mobile devices, as well as robots. Watson will be hosted by SoftBank’s data centers across the country.

News Article | August 25, 2014

NEWS ANALYSIS: VMware previews updated products for CIOs, IT managers, storage administrators and the CFOs who love to pay for it all. SAN FRANCISCO--Despite all the talk, all the marketing hype and all the new cloud products and services coming into the marketplace in the last eight or so years, a whopping 92 percent of the world's IT is still being handled on-premises. You thought the cloud was taking over the world? Maybe in the future, but certainly that's not the case right now. Most IT thought leaders are generally in agreement on this: Over time--likely during the next three to five years as IT buying cycles set in--that 92 percent figure slowly will be lessened as more companies come to deploy hybrid and public clouds for their employees, business partners and customers. This, of course, requires agile software and easy, safe movement of data. And this, in turn requires more virtualization, high bandwidth and cloud services. Virtual data centers are at the center of this IT future. As it happens, VMware is quite happy to tell you about their latest products and services for those new-gen data centers. Each year at this time, the Palo Alto, Calif.-based company stages VMworld , the huge IT conference here at the Moscone Center that signals the end of the summer for a lot of people.On Aug. 25, CEO Pat Gelsinger, President and COO Carl Eschenbach, and Senior Vice President of Hybrid Cloud Solutions Bill Fathers announced on Day 1 of the conference a phalanx of new and updated products for CIOs, IT managers, storage administrators, security specialists and the CFOs who love to pay for it all. In addition to the requisite new versions of software, VMware also announced a new joint initiative with newcomer Docker, Google and corporate cousin Pivotal to incorporate containers--a legacy software structure that isolates distributed applications in development to reduce complications--in VMware virtual machines. This will be good news to many IT managers with older systems because they won't have to discard their container-based workflows any time soon if they plan to move to newer virtualized systems built by VMware. (For more detail, see Sean Michael Kerner's story here.) There was a list of other items announced Aug. 25. They included: --, a re-branding and augmentation of VMware Hybrid Cloud Service. This all-purpose hybrid cloud platform is a conglomeration of existing VMware products and several new ones added through recent acquisitions, including mobile deployment with AirWatch. --: This is a new rack-built, commodity x86-server-based appliance with server and/or storage hardware to be supplied by Dell, EMC, Fujitsu, SuperMicro, Japan's NetOne and China's Inspur. It's aimed at midrange-size enterprises. EVO:RAIL is designed for data center simplification with hyper-converged infrastructure appliances. "Take it out of the box, roll it up, plug it in--it's ready in 15 minutes for a full VM operation," CEO Pat Gelsinger said in the introduction. --: vCloud Suite's new release version jumps from 5.5 to 5.8. VMware didn't say what happened to v5.6 and v5.7. vCloud was released a few years ago as a combination of products into one SKU and license code. In the latest version, VMware has added improvements in business continuity and disaster recovery with policy-based provisioning of disaster recovery data tiers and increased scalability of protection and recovery capabilities.vCloud Suite 5.8's Big Data Extensions now support Hadoop 2 for big data workloads and features  customizable provisioning of NSX firewall and routing services; proactive support is now provided by Support Assistant, a free vCenter plug-in that tries to identify issues before problems occur. Additional announcements Aug. 25 at VMworld included the announcement of a vSphere v6.0 beta, a VSAN 2.0 beta, a new VMware Integrated OpenStack, VMware NSX 6.1 and a new VMware vRealize Suite.One of the significant announcement here involves a new storage service, vCloud Air Object Storage. VMware vCloud Air has two block storage tiers, Standard and SSD-Accelerated, which look to a virtual machine like a block volume. Object Storage acts as low-speed, long-term storage for buckets of unstructured data and isn’t associated with any specific virtual machine. VMware vCloud Air Object Storage is a highly scalable, cost-effective, and dependable storage solution that can easily scale up to petabytes, and users pay only for the storage they use. Based on EMC's ViPR storage, it offers the popular S3 API, including lifecycle management and versioning features to simplify and reduce management overhead. "Data durability is 11 nines per object, and data can be accessed via HTTP and HTTPS," VMware's Mathew Lodge wrote in a company blog post. "One of the differentiating features is support for very large objects up to 20TB in size, in line with the rapid growth in size for media files and other unstructured data. We have a number of other innovations in the pipeline, and will talk about those closer to release," Lodge said. Object Storage will be available in beta by the end of September, Lodge said.Another vCloud Air feature, Virtual Private Cloud OnDemand, will provide customers with on-demand access to vCloud Air with the swipe of a credit card. Billing is provided in arrears for services consumed. Initially offered as a qualified beta, customers now can apply for a vCloud Air Virtual Private Cloud OnDemand account here . VMware's year-old hybrid cloud platform has grown fairly quickly to serve U.S., European and Asia-Pacific enterprises. Now with 11 data centers globally, VMware announced its hybrid cloud expansion in the Asia-Pacific region via joint venture with SoftBank Telecom Corp. and SoftBank Commerce & Service Corp. (SoftBank C&S) that brought vCloud Air to Japan. In addition, VMware has announced a strategic partnership with China Telecom to build a hybrid cloud service in Beijing. eWEEK will take closer looks at each of these products later in the week as VMworld continues, which it does through Aug. 28.

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